Fourdrinier drainage foil assembly

ABSTRACT

A PORTION OF A PAPERMAKING MACHINE IS DISCLOSED WHERE PAPER STOCK DISCHARGE FROM A HEADBOX IS DEPOSITED UPON A FOURDRINIER TYPE WEB FORMING WIRE PROVIDED WITH DRAINAGE FOIL ASSEMBLIES BENEATH THE WIRE (SUBSTITUTED FOR TABLE ROLLS), AND A FOIL ASSEMBLY IS SUPPORTED BENEATH THE WIRE BY A SUPPORT MECHANISM CARRIED ON RAILS BENEATH AND PARALLEL TO THE EDGES OF THE WIRE. THE ASSEMBLY INCLUDES A BODY WHICH IS CONNECTED TO THE SUPPORT MECHANISM AND A FOIL CAP MOUNTED ON TOP OF THE FOIL BODY. THE FOIL BODY AND FOIL CAP ARE PROVIDED WITH A DOVETAIL CONNECTION THEREBETWEEN, A CLAMP BAR OVERLAPPING BOTH THE BODY AND CAP AND PIVOTALLY CONNECTED TO THE BODY, AND A FLUID PRESSURE INFLATABLE TUBE BETWEEN THE BAR AND BODY ON A SIDE OF THE PIVOTAL CONNECTION OPPOSITE THE CAP, THE SECURELY CLAMPING THE CAP TO THE BODY UPON INFLATING THE TUBE.

April 27,1971 REYNOLDS ET AL I 3,576,716

' FOURDRINIER DRAINAGE FOIL ASSEMBLY Filed June '12, 1969 United StatesPatent 3,576,716 FOURDRINIER DRAINAGE FOIL ASSEMBLY George E. Reynolds,Fred J. Gedelner, and Lee R. Loughran, Appleton, Wis., assignorstoAllis-Chalmers Manufacturing Company, Milwaukee, Wis.

Filed June 12, 1969, Ser. No. 832,703 Int. Cl. D21f 1/26 US. Cl. 162-3526 Claims ABSTRACT OF THE DISCLOSURE A portion of a papermaking machineis disclosed where paper stock discharge from a headbox is depositedupon a Fourdrinier type web forming wire provided with drainage foilassemblies beneath the wire (substituted for table rolls), and a foilassembly is supported beneath the wire by a support mechanism carried onrails beneath and parallel to the edges of the wire. The assemblyincludes a body which is connected to the support mechanism and a foilcap mounted on top of the foil body. The foil body and foil cap areprovided with a dovetail connection therebetween, a clamp baroverlapping both the body and cap and pivotally connected to the body,and a fluid pressure inflatable tube between the bar and body on a sideof the pivotal connection opposite the cap, for securely clamping thecap to the body upon inflating the tube.

CROSS REFERENCE TO RELATED PATENT APPLICATION A foil body and capassembly with a flexible strip spring for securing a foil cap to a foilbody, is the subject of a copending US. patent application entitledFourdrinier Drainage Foil Assembly, Ser. No. 672,117, filed Oct. 2,1967, now Pat. No. 3,515,636.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates to papermaking machines having drainage foils, deflectors,forming boards or the like, beneath a Fourdrinier type web forming wireand in particular to a foil assembly including a body carrying aremovable and replaceable foil cap beneath the Fourdrinier wire.

Description of the prior art A concept involved in this invention isthat of providing blades, now commonly called drainage foils, beneath aFourdrinier wire in the position formerly occupied by table rolls, toachieve superior drainage of water through the bottom of the wire. Theevolution of this concept to present day forms is illustrated by thefollowing patents: British Pat. 399,739 in 1933; British Pat. 717,798 in1954; US. Pat. 2,744,454 in 1956; US. Pats. 3,017,930 and 3,027,941 in1962; US. Pat. 3,140,225 in 1964; and US. Pats. 3,165,440 and 3,201,308in 196 5. In all of these prior art arrangements some provision is madefor re placing a foil after it has become worn but with a considerablevariation in the speed and convenience of such replacement.

SUMMARY OF THE INVENTION It is a primary object of the present inventionto provide a new and improved drainage foil assembly for promoting waterremoval through the bottom of a Fourdrinier web forming wire.

Another object of the present invention is to provide a drainage foilassembly or the like with a new and improved arrangement for quicklyreplacing a removable cap.

3,576,716 Patented Apr. 27, 1971 Another object of the present inventionis to provide a new and improved arrangement for mounting a removablefoil cap on a body supported below the bottom surface of a Fourdrinierwire.

According to a preferred embodiment of the present invention, aFourdrinier wire drainage foil assembly includes a body portionsupported in a generally horizontal position below a Fourdrinier wire,with a foil cap mounted on top of the foil body. The foil cap isattached to the body by a dovetail tongue and groove type joint. Thedovetail tongue is defined by the bottom surface of the foil cap andprojects downwardly. The top surface of the foil body defines a portionof the dovetail groove including a generally horizontal groove bottomsurface and one groove wall angularly inclined upwardly from the bottomsurface in a direction to be partly over the bottom surface. A clamp baris pivotally connected to the body adjacent the groove surface on theopposite side thereof from the one groove wall defined by the foil body.The clamp bar is arranged to project upwardly from the groove bottomsurface and is inclined toward the one groove wall defined by the body.The clamp bar therefore provides a second groove wall and therebycompletes the formation of a dovetail groove complementary with thetongue of the foil cap. The clamp bar is biased toward the groove walldefined by the body by inflating a fluid pressure inflatable tubebetween the bar and body below the level of bottom surface of the grooveand therefore firmly holds the dovetail tongue of the foil cap butallows easy withdrawal and insertion of the tongue through an open endof the slot upon deflating the tube.

Other features and objects of the invention that have been attained willappear from the more detailed description of an embodiment of theinvention shown in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a diagrammatic side elevationview of a portion of a papermaking machine showing a portion of aheadbox, a breast roll, Fourdrinier wire and drainage foil assembliesaccording to the present invention;

FIG. 2 is an enlarged and fragmentary view of one of the drainage foilassemblies of FIG. 1, showing the assembly in greater detail; and

FIG. 3 is a view of another embodiment of a drainage foil assemblyaccording to the present invention.

* DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing andFIG. 1 in particular, a portion of a papermaking machine is shownwherein a headbox 1 discharges pulp through a slice opening 2 to depositthe pulp on a Fourdrinier wire 3 as it leaves a breast roll 4 that isturning in the direction indicated by the arrow. A plurality of drainagefoil assemblies 5 are shown arranged beneath the wire 3 and mounted onside rails 6.

Referring to FIG. 2, the foil support assembly 5 is shown as having asupport member 10 connected to rail 6 (as-shown in FIG. 1), a foil body14, and a replaceable foil cap 16 having a leading knife-edge 11,mounted on top of the foil body in a manner that will appear as thedescription of the disclosed apparatus proceeds. The term leading asherein used to describe knife-edge 11 refers to the orientation shown inFIG. 1 where it is shown that the knife-edge 11 is the lead edge withrespect to the approach of wire 3 toward foil cap 16.

The foil cap 16 is attached to the foil body 14 by a dovetail tongue andgroove type joint. As shown in FIG. 2 a dovetail tongue 17 is formed onthe bottom of foil cap '16 and has a generally horizontal surface 18, afirst tongue wall 19 spaced back of the leading knife-edge 11, and asecond tongue wall spaced back of the first wall 19, to definetherebetween the downwardly projecting dovetail tongue 17. A third wall21 defined by cap 16 is spaced ahead of the second wall 20 andcooperatees therewith to define a slot 22. The tongue walls 19, 20 areinclined downwardly in diverging relation to each other to form with thesurface 18 the dovetail tongue configuration 17. A portion of a dovetailgroove 23 is defined on top of said foil body 14 by a generallyhorizontal surface 24 and a groove wall 25. A clamp bar 26 is attachedto the foil body 14 by screws 27 projecting through a hole 28 in bar 26.The hole 28 is of slightly larger diameter than the shaft of screws 27to permit bar 26 to pivot about screws 27 as indicated by the arrows 29and 30. The bar 26 has a portion 26a that projects upwardly from groovesurface 24 in converging relation to wall and a lip 26b of bar 26projects horizontally from portion 26a into slot 22. Wall 25, surface 24and bar 26 complete the formation of the dovetail groove 23 in foil body14 which is complementary to dovetail tongue 17.

A groove 35 is defined in body 14 and open in a di-. rection facingclamp bar 26. The groove 35 is arranged below the level of screws 27 andextends parallel to the leading edge 11. A collapsible-inflatable tube36 is arranged within slot 35 and connected to a suitable adjustablesource of fluid pressure (not shown) for providing selected positivepressure or negative pressure (i.e. drain) to in flate or collapse tube36. Tube 36 may be made of any rubber or rubber-like material.

Referring to FIG. 3, another embodiment of the present invention isshown, in which walls 20, 21, slot 22, bar 26, screws 27, groove 35 andtube 36 are all located on the leading edge 11 side of the assembly 5rather than on the side opposite edge 11 as shown in FIG. 2.

In time the top surface of the foil cap 16 and its lead ing knife-edgewill become worn and require replacement. To remove the cap 16 fluidpressure is released and drained from tube 36 causing tube 36 to deflateand collapse. As tube 36 collapses within groove 35, the clamp bar 26will pivot about screws 27 in the direction indicated by arrow 29 andthe portion 26a of bar 26'above screws 27 will move away from cap tonguewall 20 and since hole 28 is larger than the shaft of screw 27 the barportion 26b is not pulled downwardly in slot 22, the cap 16 is thenloosely carried on body 14. The cap 16 may then be easily withdrawn in adirection transverse to the wire 3 shown in FIG. 1.

A replacement cap 16 may'then be put in place by inserting and slidingtongue 17 indovetail groove 23.

The cap 16 is then securely clamped in position by inflating tube 36causing it to expand within groove 35 and push bar 26 to pivotabout'screws 27 in the direction indicated by arrow 30. Pivoting thebottom portion of clamp bar 26 in the direction indicated by arrow movesportion 26b into slot 22 and the upper portion 26a of bar 26 againsttongue wall 20 and pushes tongue 17 against groove wall 25 and pullstongue 17 down on groove surface 24 to thereby securely clamp cap 16 tofoil body 14.

It may be desired to operate the described apparatus when the cap 16does not require replacement but balling particles of stock fibers aredisturbing desired sheet formation on wire 3. Under such circumstancestube 36 may be defiated and cap 16 slid back and forth to dislodge suchballing particles.

There are also times when it may be desired to operate the paper machinewith one or more of the foil assemblies inoperative. Under suchcircumstances tube may be deflated, foil cap 16 withdrawn and a fillerinsert having a top surface indicated by broken line 40 in FIG. 3, maybe inserted and securely held in place by again inflating tube 35. Thefiller insert 40 will eliminate a buildup of material in dovetail groove23 of an assembly 5 that is not in use, and the level of the surface 40is at a distance below wire 3 suflicient to allow ample clearance.

'From the foregoing detailed description of the present invention it hasbeen shown how the objects of the invention have been attained in apreferred manner. However, modifications and equivalents of thedisclosed concepts such as readily occur to those skilled in the art areintended to be included within the scope of this invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A Fourdrinier 1Wire drainage foil assembly and the like including apair of elements one of which is a foil body adapted for support in agenerally horizontal position and the other of which is a cap mounted ontop of said body and connected thereto, said body having a top surfaceand said cap having a bottom surface cooperating to define therebetweena dovetail tongue and a portion of a dovetail groove, said portion ofsaid dovetail groove including a generally horizontal groove surface anda first transverse groove wall, and a clamp bar loosely connected by apivotal connection to the assembly adjacent said groove surface on theopposite side thereof from said first groove wall and with said clampbar having a portion projecting away from said groove surface in adirection converging toward said first groove wall to provide a secondwall for said groove and thereby define a dovetail groovecomplementarily engaging said dovetail tongue, the dovetail tonguedefines a slot open in a generally horizontal direction toward the saidprojecting portion of the clamp bar, the projecting portion of the clampbar is provided with a generally horizontally extending lip projectingaway from the bar and in register with the slot defined in the dovetailtongue, and a fluid pressure inflatable tube between the clamp bar andthe assembly on a side of the pivotal connection remote from saidprojecting portion of said bar and said lip, for inserting the lip intothe slot and then securely clamping the cap to the body upon inflationof said tube.

2. A drainage foil assembly according to claim I having a tubeholdinggroove for the inflatable tube and within which the tubecollapses upon deflation.

3. A drainage foil assembly according to claim 1 in which said dovetailtongue projects downwardly from the bottom surface of said foil cap,said portion of said dovetail groove is defined in the'top of said foilbody, and said clamp bar is connected to said body with the saidprojecting portion of said bar projecting upwardly from 'the pivotalconnection to complete the formation of a dovetail groove in said foilbody complementary to said dovetail tongue projecting from said foilcap.

4. A drainage foil assembly according to claim 3 in which the downwardlyprojecting dovetail tongue defines a slot open in a generally horizontaldirection toward the said upwardly projecting portion of the clamp bar,and the said upwardly projecting portion of the clamp bar is providedwith a generally horizontally extending lip projecting away from the barand into the slot defined in the dovetail tongue.

5. A drainage foil assembly according to claim 1 in which said foil caphas a leading knife-edge and said clamp bar is connected to the assemblyon a side thereof opposite said knife-edge.

6. A drainage foil assembly according to claim 1 in which said foil caphas a leading knife-edge and said clamp bar is connected to the assemblyon the knifeedge side of the assembly.

References Cited UNITED STATES PATENTS 3,027,940 4/1962 Dunlap 162354X3,393,124 7/1968 Klingler et al. 162-352 REUBEN FRIEDMAN, PrimaryExaminer T. A. GRANGER, Assistant Examiner

